The (-) form of deprenyl, also known as selegiline (phenylisopropyl-methylpropynylamine) or its pharmaceutically acceptable salts, are used in the form of tablets as an antiparkinsonian drug.
A large number of forms for administration of selegiline have been described in the patent literature. Transdermal administration forms including, for example, patches, are disclosed in European patents Nos. 404 807; 406 488; 509 761; 591 432; 593 807; 617 515; 647 137; 683 668; 655 900; WO 96/02239; WO 95/18603; and WO 94/23707.
Drug forms for the controlled release of selegiline, for example in the form of tablets, are described in European patent No. 582 186; in WO 96/01612; and in U.S. Pat. No. 5,484,608, and osmotically acting release systems are described in U.S. Pat. No. 5,128,145; and normal-release oral formulations are described in WO 96/22435.
Patent application WO 96/12472 discloses a liposomal composition which comprises the active ingredient selegiline.
Buccal and sublingual forms of administration are disclosed in WO 97/-17067. WO 95/07070 describes effervescent formulations which, to avoid the insoluble residues of tricalcium citrate which can be formed when effervescent formulations are dissolved, comprise at least two different edible acids.
WO 93/00886 describes effervescent tablets having good storage stability, for example alkali-sensitive active ingredients such as acetylcysteine, captopril and minoxidil. The tablets comprise an effervescent base containing a solid edible organic acid as carrier crystals, an alkali metal carbonate or bicarbonate and an alkali metal salt of the acid. Two layers are applied onto the carrier crystals. The first layer contains a different acid than the carrier crystals, and the second layer contains the alkali metal salt of one of the two acids.
Selegiline is unstable in alkali-containing effervescent formulations. Even a multilayer construction is not sufficient for stabilization. Alkali carbonates and bicarbonates are more basic than alkaline earth carbonates, such as calcium carbonate. There are no suitable effervescent formulations known for selegiline, which is an alkali-sensitive active ingredient. This may partly be due to the fact that such formulations were so far not successful due to the instability of selegiline, as also shown in FIG. 1.
The therapeutic treatment of various disorders requires, in particular in elderly people, a very frequent and in many cases even the permanent taking of pharmaceuticals.
Parkinson patients usually have problems due to strong tremor when swallowing tablets with liquids. Likewise, taking of tablets is very difficult for patients that have difficulties swallowing.
Therefore there is a need for novel solid, rapidly disintegrating oral dosage forms of administration, particularly effervescent formulations in the form of soluble tablets, buccal tablets or soluble granules which ensure easy administration, even for example, for elderly patients.